Analysis Of The S Phase Checkpoint In Higher Eukaryotes

高等真核生物 S 期检查点的分析

• 批准号: 6541235
• 负责人: MARY C. DASSO
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6541235
• 关键词: DNA replication; Xenopus oocyte; cell cycle; cell growth regulation; enzyme activity; eukaryote; guanine nucleotide binding protein; guanine nucleotide exchange factors; guanosinetriphosphatases; messenger RNA; molecular cloning; protein structure function; small nuclear ribonucleoproteins

SUMO-1 is a ubiquitin-like protein. SUMO-1 can be covalently conjugated to other proteins through an isopeptide linkage in a manner similar to ubiquitin. A number of SUMO-1 conjugation substrates have been reported in vertebrates to date; these include RanGAP1, RanBP2, PML, Sp100, IkBa, HIPK2, p53, topoisomerase I, c-Jun and the Werner's Syndrome gene product. Western blotting analysis suggests that the reported SUMO-1 substrates are a subset of the total number of cellular proteins that are conjugated to SUMO-1 in vivo. The SUMO-1 conjugation pathway utilizes enzymes that show both sequence similarity and structural conservation with ubiquitin activating (E1) and conjugating (E2) enzymes. Moreover, biochemical analysis suggests that ubiquitin and SUMO-1 enzymes carry out their functions using similar enzymatic mechanisms. However, none of the enzymes characterized to date act in both the ubiquitin and SUMO-1 conjugation pathways. We are studying the SUMO-1 pathway in vertebrates. We are particularly interested in the regulation of this pathway during the cell cycle and its role in controlling the Ran GTPase activating protein RanGAP1 through conjugation. Our goals are to understand this pathway and its regulation at a molecular level, to determine whether and how it regulates mitosis in vertebrates. Toward this goal, we have analyzed the localization, abundance and behavior of enzymes involved in SUMO-1 conjugation and deconjugation, as well as the disruption of this pathway in disease states (acute promyelocytic leukemia) and through the action of viral proteins (HSV-1 ICP0).

SUMO-1是一种泛素样蛋白。SUMO-1可以通过类似于泛素的方式通过异肽键与其他蛋白质共价缀合。迄今为止，在脊椎动物中已经报道了许多SUMO-1缀合底物;这些包括RanGAP 1、RanBP 2、PML、Sp100、IkBa、HIPK 2、p53、拓扑异构酶I、c-Jun和Werner综合征基因产物。Western印迹分析表明，报告的SUMO-1底物是在体内与SUMO-1缀合的细胞蛋白总数的子集。SUMO-1缀合途径利用与泛素活化（E1）和缀合（E2）酶显示序列相似性和结构保守性的酶。此外，生物化学分析表明，泛素和SUMO-1酶使用类似的酶机制执行其功能。然而，迄今为止表征的酶中没有一种在泛素和SUMO-1缀合途径两者中起作用。我们正在研究脊椎动物中的SUMO-1通路。我们特别感兴趣的是，在细胞周期中，这一途径的调控和它的作用，通过共轭控制的Ran GT3激活蛋白RanGAP 1。我们的目标是在分子水平上了解这一通路及其调控，以确定它是否以及如何调节脊椎动物的有丝分裂。为了实现这一目标，我们分析了参与SUMO-1结合和去结合的酶的定位、丰度和行为，以及疾病状态（急性早幼粒细胞白血病）和病毒蛋白（HSV-1 ICP 0）作用下该途径的破坏。